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Journal Articles

Hydrogen gas measurements of phosphate cement irradiated during heat treatment

Irisawa, Keita; Kudo, Isamu*; Taniguchi, Takumi; Namiki, Masahiro*; Osugi, Takeshi; Nakazawa, Osamu

QST-M-16; QST Takasaki Annual Report 2017, P. 63, 2019/03

no abstracts in English

Journal Articles

The Hydrogen gas generation by electron-beam irradiation from ALPS adsorbents solidified by several inorganic materials

Sato, Junya; Suzuki, Shinji*; Kato, Jun; Sakakibara, Tetsuro; Meguro, Yoshihiro; Nakazawa, Osamu

QST-M-2; QST Takasaki Annual Report 2015, P. 87, 2017/03

no abstracts in English

Journal Articles

Irradiation experiments of simulated wastes of carbonate slurry

Nagaishi, Ryuji; Motooka, Takafumi; Yamagishi, Isao

Proceedings of 2016 EFCOG Nuclear & Facility Safety Workshop (Internet), 6 Pages, 2016/09

Overflow of water from waste storage tanks of High Integrity Containers (HIC) in the multi-nuclide removal equipment (ALPS) was discovered at Fukushima Daiichi NPS in April of last year. The mechanism of overflow was not understood very much at that time. To elucidate that for chemical safety in the waste storage, irradiation experiments of simulated carbonate slurry by Co-60 $$gamma$$-rays have been conducted in CLADS, JAEA in cooperation with TEPCO, TOSHIBA and KURITA. Hydrogen molecule was the main radiolytic gas product in the slurry, and its amount was enhanced by dissolved species of not only halide ions as seawater components but also carbonate ion as an additive for co-precipitation at a basic condition. The bubbles of molecules were further formed and almost held in the slurry without stirred. These sequentially led to the expansion of slurry, and then to its separation into the shrunk one and supernatant water, which was little accumulated without irradiated.

JAEA Reports

The Activity of sulfate reducing bacteria in bentonite and the effect of hydrogen sulfide on the corrosion of candidate materials for overpacks

; Kawasaki, Manabu*; *

JNC-TN8400 2001-011, 62 Pages, 2001/03

JNC-TN8400-2001-011.pdf:6.42MB

The corrosion of metallic materials used in natural environment are sometimes affected by microbial action. It is apprehended that microorganism living in deep underground or brought from ground surface during excavation makes an impact on overpack material for geological disposal of high-level radioactive waste. Sulfate reducing bacteria (SRB) is known to be one of the most representative microorganism which affects the corrosion of metals. In this study, the behavior of growth of SRB was investigated at first under the presence of bentonite as a main component of buffer material which encloses the overpack. The results of the tests showed that the population of SRB after the culture in synthetic sea water mixed with bentonite decreased with increasing the ratio of bentonite/solution. SRB was hardly grown in medium whose bentonite/solution ratio exceeded 1000g/l. As a conservative case, the effects of sulfide on the corrosion of overpack materials were also studied assuming high activity of SRB. Carbon steel, copper and titanium specimens were immersed in synthetic sea water purging 0.1MPa H$$_{2}$$S gas and the corrosion behavior was compared with the results in N$$_{2}$$ gas purging environment. Obvious effect of sulfide on the corrosion of carbon steel was not observed, but the corrosion rates of copper specimens were accelerated several hundred times by purging H$$_{2}$$S gas. The absorption of hydrogen into titanium specimens was not affected by purging H$$_{2}$$S gas, but the difference of hydrogen absorption between pure titanium and titanium alloy containing 0.06%-Pd was observed.

JAEA Reports

A Preliminary assessment of gas diffusion and migration

Tanai, Kenji; Sato, Haruo; *; *

JNC-TN8400 99-045, 108 Pages, 1999/11

JNC-TN8400-99-045.pdf:4.48MB

In the anaerobic environment in the deep underground water, carbon-steel overpack corrodes and generates molecular hydrogen. It is conceivable that this hydrogen either dissolves into the porewater of the buffer and migrates through the buffer. If the rate of aqueous diffusion of hydlogen is too low compared to the rate of hydrogen generation, the concentration of hydrogen at the overpack surface will increase until a solubility limit is attained and a free hydrogen gas phase forms. It is possible that the pressure in this accumulating gas phase will increase, affecting the stability of the buffer or the surrounding rock mass. There is also a concern of possible effects on nuclide migration, as it is also conceivable that the flow of gas could push out radionuclide-bearing porewater in the buffer when it floes through the buffer. As such, experimental and analytical study must be carried out on such phenomenon to evaluate such potential phenomena. (1)Diffusion experiment of dissolved hydrogen. According to the test result concerning the effective diffusion coefficient of the dissolved hydrogen in buffer material, the effective diffusion coefficient of reference buffer material (70wt% bentonite + 30wt% sand mixture, dry density 1.6Mg m$$^{-3}$$) ranges from 10$$^{-10}$$ m$$^{2}$$ s$$^{-1}$$ to 10$$^{-11}$$ m$$^{2}$$s$$^{-1}$$. The value of the effective diffusion coefficient measured for a dry density of 1.8 Mg m$$^{-3}$$ is slightly smaller than the value in that for a dry density 1.6 Mg m$$^{-3}$$. And the effective diffusion coefficient at 60$$^{circ}$$C tends to have slightly larger value than that at 25$$^{circ}$$C. Test results from the foreign countries show the diffusion coefficient in the range between 10$$^{-9}$$ m$$^{2}$$s$$^{-1}$$ to 10$$^{-12}$$m$$^{2}$$s$$^{-1}$$. Basically, these test results reported here are in the same range as these other results. (2)Gas permeability. Studies of the gas permeabinty of buffer material have been carried out by Pusch et al., Volckaert ...

Journal Articles

Effects of environmental factor on gas evolution behavior from Al in simulating mortar environments

Hashizume, Shuji; Matsumoto, Junko; Bamba, Tsunetaka

Zairyo To Kankyo, 47(10), p.638 - 644, 1998/00

no abstracts in English

JAEA Reports

None

Wada, Ryutaro*; Nishimura, Tsutomu*; *; *; *

PNC-TJ1058 97-003, 33 Pages, 1997/03

PNC-TJ1058-97-003.pdf:1.02MB

None

Journal Articles

Electron beam treatment of flue gas from a municipal waste incinerator

Tokunaga, Okihiro; Aoki, Yasushi; Sato, Shoichi; *; *; *; *

Applications of Isotopes and Radiation in Conservation of the Environment, p.105 - 114, 1992/00

no abstracts in English

Journal Articles

Use of a hollow cathode in a duoPIGatron hydrogen ion source

; *; *

Japanese Journal of Applied Physics, 19(9), p.1703 - 1710, 1980/00

 Times Cited Count:6 Percentile:64.33(Physics, Applied)

no abstracts in English

Journal Articles

Construction and performance of a hydrogen secondary cooling system, 1; Facility and performance of the components

; Nekoya, Shinichi; Emori, Kouichi; Ogawa, Masuro; Ouchi, Mitsuo; ; Sanokawa, Konomo; *; *; *; et al.

Nippon Genshiryoku Gakkai-Shi, 22(3), p.181 - 188, 1980/00

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Construction and performance test of a hydrogen secondary cooling system, 2; Results of the performance tests

Hishida, Makoto; Takizuka, Takakazu; Ogawa, Masuro; Nekoya, Shinichi; Emori, Kouichi; Ouchi, Mitsuo; Sanokawa, Konomo

Nippon Genshiryoku Gakkai-Shi, 22(5), p.326 - 334, 1980/00

 Times Cited Count:1 Percentile:76.66(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Behavior of hydrogen gas in welds of aliminium

; Ando, Yoshio*

Yosetsu Gakkai-Shi, 32(2), p.91 - 100, 1963/00

no abstracts in English

Oral presentation

Evaluation of hydrogen gas generation from inorganic solidified samples containing simulated ALPS slurries by electron beam irradiation

Sato, Junya; Suzuki, Shinji; Nakagawa, Akinori; Kato, Jun; Sakakibara, Tetsuro; Meguro, Yoshihiro; Nakazawa, Osamu

no journal, , 

no abstracts in English

Oral presentation

Irradiation experiments of simulated carbonate slurry in HIC, 3; Studies on radiolysis behavior of simulated carbonate slurry

Nagaishi, Ryuji; Motooka, Takafumi; Yamagishi, Isao; Inoue, Masao; Matsumura, Taichi

no journal, , 

no abstracts in English

Oral presentation

Basic study on production of hydrogen gas by radiolysis of the carbonate slurry generated from the multi-radionuclide removal system

Arai, Yoichi; Hinai, Hiroshi; Koma, Yoshikazu; Ikeda, Akira*; Obata, Masamichi*; Shibata, Atsuhiro; Nomura, Kazunori

no journal, , 

no abstracts in English

Oral presentation

Evaluation of hydrogen gas production at transient criticality in uranyl nitrate solution

Yoshida, Ryoichiro; Yamane, Yuichi; Abe, Hitoshi

no journal, , 

At criticality accident on solution fuel, it is known that hydrogen gas is generated with nuclear fission. Because of the temporary decrease effect on power through density decrease and the possibility which causes secondary accident such as explosion, it is important on safety evaluation at criticality accident that to estimate relating the amount of hydrogen gas and the number of nuclear fissions. The time history data of concentration of hydrogen gas in vent gas when the transition critically used uranyl nitrate solution, which was obtained from Transient Experiment Critical Facility (TRACY), could not be explained by simple diffusion, because of peak about 500 seconds later from reactivity addition and after that long tail. Then, calculating the transition behavior of hydrogen gas in reactor core tank by combining multiple models such as Taylor dispersion, and evaluating concentration of hydrogen gas result reproducing the measured value well. The amount of hydrogen gas also evaluated 4 mol per 10$$^{18}$$ fissions.

Oral presentation

Study on H$$_{2}$$ gas production by radiolysis of carbonate slurry generated from Multi-Radionuclide Removal System

Arai, Yoichi; Hinai, Hiroshi; Koma, Yoshikazu; Shibata, Atsuhiro; Nomura, Kazunori

no journal, , 

Multi-Radionuclide Removal System (MRRS) has been utilized for decontaminate of the radioactive contaminated water in Fukushima Daiichi Nuclear Power Station (1F). The secondary wastes including iron hydroxide, carbonate and used adsorbents are packed in the High Integrity Container (HIC). It was reported that the radioactive liquid was overflowed in several HICs. This phenomenon was only observed in HICs containing the carbonate slurry waste. It was inferred that volume increase of wastes due to gas generation caused by the water radiolysis. However, the gas generation behavior was not well known. Therefore, it is important to investigate gas generation behavior of radioactive carbonate slurry waste. Ten ml of the carbonate slurry waste was put into the sealing vial. After standing sample for certain duration, concentration of hydrogen was measured by gas-chromatography. Total amounts of hydrogen gas produced from the slurry was proportionally increased with time. Measured G-value was equivalent to the theoretical G value. This result showed that hydrogen gas generated by water radiolysis in radioactive carbonate slurry waste.

Oral presentation

The Hydrogen gas generation by electron-beam irradiation from ALPS adsorbents solidified by several inorganic materials

Sato, Junya; Suzuki, Shinji*; Kato, Jun; Sakakibara, Tetsuro; Meguro, Yoshihiro; Nakazawa, Osamu

no journal, , 

no abstracts in English

Oral presentation

Studies on radiolysis behavior of carbonate slurry under Co-60 $$gamma$$-ray irradiation

Nagaishi, Ryuji; Motooka, Takafumi; Yamagishi, Isao; Inoue, Masao*; Matsumura, Taichi

no journal, , 

no abstracts in English

Oral presentation

Influence of $$^{60}$$Co $$gamma$$-ray on characteristics of phosphate cements synthesized during dehydration

Irisawa, Keita; Kudo, Isamu*; Taniguchi, Takumi; Namiki, Masahiro*; Osugi, Takeshi; Nakazawa, Osamu

no journal, , 

no abstracts in English

24 (Records 1-20 displayed on this page)